A battery stores and releases electrical energy by relying on the chemical diffusion of ions between an anode electrode and a cathode electrode. During storage of electrical energy, ions flow from the cathode electrode to the anode electrode in response to a voltage potential placed across the battery's terminals. Conversely, during release of electrical energy, ions flow from the anode electrode to the cathode electrode as the battery drives current through an electrical load battery. An electrolyte serves as a transport medium to facilitate chemical diffusion between the anode electrode and the cathode electrode.
The battery employs an electrode assembly to control chemical diffusion between the anode electrode and the cathode electrode. The electrode assembly includes a separator disposed between the anode electrode and the cathode electrode. The separator serves to isolate the anode electrode from the cathode electrode and provides a permeable matrix through which the electrolyte (and ions therein) can diffuse. However, repeated storage and release of electrical energy from the battery may induce the electrode assembly to irreversibly swell. Such swelling may be caused by chemical changes in the electrode assembly, the electrolyte, or both. Battery housings are desired that can accommodate swelling of an electrode assembly.